Microbial co-occurrence complicates associations of gut microbiome with US immigration, dietary intake and obesity

Background Obesity and related comorbidities are major health concerns among many US immigrant populations. Emerging evidence suggests a potential involvement of the gut microbiome. Here, we evaluated gut microbiome features and their associations with immigration, dietary intake, and obesity in 2640 individuals from a population-based study of US Hispanics/Latinos. Results The fecal shotgun metagenomics data indicate that greater US exposure is associated with reduced ɑ-diversity, reduced functions of fiber degradation, and alterations in individual taxa, potentially related to a westernized diet. However, a majority of gut bacterial genera show paradoxical associations, being reduced with US exposure and increased with fiber intake, but increased with obesity. The observed paradoxical associations are not explained by host characteristics or variation in bacterial species but might be related to potential microbial co-occurrence, as seen by positive correlations among Roseburia, Prevotella, Dorea, and Coprococcus. In the conditional analysis with mutual adjustment, including all genera associated with both obesity and US exposure in the same model, the positive associations of Roseburia and Prevotella with obesity did not persist, suggesting that their positive associations with obesity might be due to their co-occurrence and correlations with obesity-related taxa, such as Dorea and Coprococcus. Conclusions Among US Hispanics/Latinos, US exposure is associated with unfavorable gut microbiome profiles for obesity risk, potentially related to westernized diet during acculturation. Microbial co-occurrence could be an important factor to consider in future studies relating individual gut microbiome taxa to environmental factors and host health and disease.

Dietary patterns of US Chinese Older Adults

A westernized diet, characterized by intake of foods high in fat and sugar, has been associated with several chronic conditions. However, the dietary pattern of US Chinese older adults is not well understood. The primary objective of this study was to determine the relationship between years of US residence and other demographic factors and the intake of foods high in fats and sugar. As part of the Population Study of Chinese Elderly, participants were given a 48-item food frequency questionnaire, which were further placed into primary food groups. Each group was then categorized into whether they consumed the food group at least once a week. The total sample was 59% female with an average age of 75, with 49% consuming fatty foods and 85% consuming sweets in the past week. Using logistic regression (N=3053), each additional year of US residence (range of 0-93 years) was associated with a higher dietary intake of fats (OR: 1.01 (95%CI:1.01-1.02)) and sweets (OR: 1.01 (95%CI:1.00-1.02)). Additionally, higher education was associated with lower consumption of fats (OR: 0.98 (95%CI:0.96, 0.99)) and higher income was associated with higher consumption of fats (OR: 1.11 (95%CI: 1.04, 1.18)). For sweets, women compared to men were 54% less likely to consume sweets in the last week (OR: 0.46 (95%CI:0.36, 0.59)), and higher education was associated a greater likelihood of consuming sweets (OR: 1.07 (95%CI: 1.05, 1.10)). Study findings suggest that immigration related factors and demographic factors may influence consumption of a westernized diet high in fats and sugars.

Live Monitoring of Inflammation Reveals Tissue and Sex-specific Responses to Western Diet and Butyrate treatment

Obesity is a current epidemic, affecting millions of individuals worldwide. Chronic obesity is characterized by a low grade systemic inflammation besides not being a classic inflammatory disease. Many studies have tried to identify inflammatory insults dysregulated by a Westernized diet consisted of high fat, high sucrose, and high cholesterol mainly focusing on production and secretion of inflammatory cytokines. The gut microbiome and derived metabolites, including the short-chain fatty acid butyrate, have received increased attention as underlying some of the obesogenic features. In the present work, we utilized a novel biosensor mouse model capable of monitoring in vivo inflammation. We observed tissue- and sex- specific caspase 1 activation patterns in obese mice and treated with butyrate. Our work utilizing a caspase-1 biosensor mouse model, flow cytometry and computational analyses and offers new mechanistic insights underlying the effect of butyrate in obesity and its complications.

Comparative Study Regarding the Adherence to the Mediterranean Diet and the Eating Habits of Two Groups—The Romanian Children and Adolescents Living in Nord-West of Romania and Their Romanian Counterparts Living in Italy

Background: The Mediterranean diet (MD) is associated with significant health benefits, including prevention of noncommunicable diseases (NCDs). Given the important migratory flow from Romania to Italy in recent decades, this study seeks to evaluate the differences between the nutritional habits of Romanian children and adolescents in Romania compared with those of Romanian children who moved to Italy or were born in Italy from both Romanian parents. Method: To assess adherence to MD, parents of Romanian children in Romania (RCR) and Romanian children in Italy (RCI) answered questions from an adapted version of the KIDMED test. Results: The results show that the high KIDMED index among RCI is significantly higher than the same index among RCR (68.09 versus 17.76, p < 0.05). RCR obtained a higher KIDMED score on different items: they had a lower consumption of fast food and sweets but an increased consumption of nuts, yogurts, and cheese. Conclusions: RCI have a better adherence to MD, but, at the same time, they are more exposed to westernized diet and practice less physical activity. Nutrition education is an important tool for improving health outcome.

Palonosetron/Methyllycaconitine Deactivate Hippocampal Microglia 1, Inflammasome Assembly and Pyroptosis to Enhance Cognition in a Novel Model of Neuroinflammation

Since westernized diet-induced insulin resistance is a risk factor in Alzheimer’s disease (AD) development, and lipopolysaccharide (LPS) coexists with amyloid β (Aβ)1-42 in these patients, our AD novel model was developed to resemble sporadic AD by injecting LPS into high fat/fructose diet (HFFD)-fed rats. The neuroprotective potential of palonosetron and/or methyllycaconitine, 5-HT3 receptor and α7 nAChR blockers, respectively, was evaluated after 8 days of daily administration in HFFD/LPS rats. All regimens improved histopathological findings and enhanced spatial memory (Morris Water Maze); however, palonosetron alone or with methyllycaconitine promoted animal performance during novel object recognition tests. In the hippocampus, all regimens reduced the expression of glial fibrillary acidic protein and skewed microglia M1 to M2 phenotype, indicated by the decreased M1 markers and the enhanced M2 related parameters. Additionally, palonosetron and its combination regimen downregulated the expression of ASC/TMS1, as well as levels of inflammasome downstream molecules and abated cleaved caspase-1, interleukin (IL)-1β, IL-18 and caspase-11. Furthermore, ACh and 5-HT were augmented after being hampered by the insult. Our study speculates that blocking 5-HT3 receptor using palonosetron overrides methyllycaconitine to combat AD-induced neuroinflammation and inflammasome cascade, as well as to restore microglial function in a HFFD/LPS novel model for sporadic AD.

Food Preferences in a Greenlandic Population

Objectives The overall aim was to describe food reward in an Inuit population in Greenland. More specifically, the objective was to first test the differences in food reward for sweet relative to savory food (taste bias) after four weeks on a traditionally Inuit diet (TID) vs a Westernized diet (WD). If no differences in taste bias were found between diet groups, we aimed to describe food reward in a pooled sample (median [IQR]). We hypothesized that participants would have higher preferences for sweet compared to savory foods. Methods After a dietary intervention in Greenland (20% of foods provided), we measured behavioral components of food reward using the Leeds Food Preference Questionnaire. The reward components, explicit liking and implicit wanting, were measured in response to images of Western foods varying in fat content and taste after four weeks on either TID or WD. A positive bias score reflected preference for sweet over savory, and oppositely a negative bias score reflected preference for savory over sweet foods. Results Participant characteristics were similar in the two diet groups (age (mean (SD): TID = 58.1 (11.5) vs. WD = 55.4 (9.5) years); sex: TID = 50% vs. WD = 54% women; body mass index (mean (SD): TID = 26.6 (5.5) vs. WD = 27.9 (4.7) kg/m2). In these preliminary, unadjusted analyses, we found no differences in explicit liking (P = 0.77) or implicit wanting (P = 0.70) bias score for sweet over savory foods after four weeks following either TID (n = 26) or WID (n = 24). Altogether, participants in the two diet groups had a greater explicit liking (−11.5 [−19.9; −2.8]) and implicit wanting (−21.6 [−44.2; −5.2]) for savory compared to sweet foods. Conclusions This is the first study to examine explicit and implicit aspects of food reward in an Inuit population. Contrary to our hypothesis, this population did not prefer sweet over savory Western foods. Funding Sources The study was supported by unrestricted grants from The Novo Nordisk Foundation. Royal Greenland and the supermarket chains Kalaallit Nunaanni Brugseni & Pilersuisoq supported the study with foods and food logistics.

A diet-specific microbiota drives Salmonella Typhimurium to adapt its in vivo response to plant-derived substrates

Background Little is known about the complex interactions between the diet, the gut microbiota, and enteropathogens. Here, the impact of two specific diets on the composition of the mouse gut microbiota and on the transcriptional response of Salmonella Typhimurium (S. Typhimurium) was analyzed in an enteritis model. Results Mice were fed for two weeks a fibre-rich, plant-based diet (PD), or a Westernized diet (WD) rich in animal fat and proteins and in simple sugars, and then infected with an invasin-negative S. Typhimurium strain ST4/74 following streptomycin-treatment. Seventy-two hours post infection, fecal pathogen loads were equal in both diet groups, suggesting that neither of the diets had negatively influenced the ability of this ST4/74 strain to colonize and proliferate in the gut at this time point. To define its diet-dependent gene expression pattern, S. Typhimurium was immunomagnetically isolated from the gut content, and its transcriptome was analyzed. A total of 66 genes were more strongly expressed in mice fed the plant-based diet. The majority of these genes was involved in metabolic functions degrading substrates of fruits and plants. Four of them are part of the gat gene cluster responsible for the uptake and metabolism of galactitol and D-tagatose. In line with this finding, 16S rRNA gene amplicon analysis revealed higher relative abundance of bacterial families able to degrade fiber and nutritive carbohydrates in PD-fed mice in comparison with those nourished with a WD. Competitive mice infection experiments performed with strain ST4/74 and ST4/74 ΔSTM3254 lacking tagatose-1,6-biphosphate aldolase, which is essential for galactitol and tagatose utilization, did not reveal a growth advantage of strain ST4/74 in the gastrointestinal tract of mice fed plant-based diet as compared to the deletion mutant. Conclusion A Westernized diet and a plant-based diet evoke distinct transcriptional responses of S. Typhimurium during infection that allows the pathogen to adapt its metabolic activities to the diet-derived nutrients. This study therefore provides new insights into the dynamic interplay between nutrient availability, indigenous gut microbiota, and proliferation of S. Typhimurium.

Nutritional Components in Western Diet Versus Mediterranean Diet at the Gut Microbiota–Immune System Interplay. Implications for Health and Disease

The most prevalent diseases of our time, non-communicable diseases (NCDs) (including obesity, type 2 diabetes, cardiovascular diseases and some types of cancer) are rising worldwide. All of them share the condition of an “inflammatory disorder”, with impaired immune functions frequently caused or accompanied by alterations in gut microbiota. These multifactorial maladies also have in common malnutrition related to physiopathology. In this context, diet is the greatest modulator of immune system–microbiota crosstalk, and much interest, and new challenges, are arising in the area of precision nutrition as a way towards treatment and prevention. It is a fact that the westernized diet (WD) is partly responsible for the increased prevalence of NCDs, negatively affecting both gut microbiota and the immune system. Conversely, other nutritional approaches, such as Mediterranean diet (MD), positively influence immune system and gut microbiota, and is proposed not only as a potential tool in the clinical management of different disease conditions, but also for prevention and health promotion globally. Thus, the purpose of this review is to determine the regulatory role of nutritional components of WD and MD in the gut microbiota and immune system interplay, in order to understand, and create awareness of, the influence of diet over both key components.

Lysates of Methylococcus capsulatus Bath induce a lean-like microbiota, intestinal FoxP3+RORγt+IL-17+ Tregs and improve metabolism

Interactions between host and gut microbial communities are modulated by diets and play pivotal roles in immunological homeostasis and health. We show that exchanging the protein source in a high fat, high sugar, westernized diet from casein to whole-cell lysates of the non-commensal bacterium Methylococcus capsulatus Bath is sufficient to reverse western diet-induced changes in the gut microbiota to a state resembling that of lean, low fat diet-fed mice, both under mild thermal stress (T22 °C) and at thermoneutrality (T30 °C). Concomitant with microbiota changes, mice fed the Methylococcus-based western diet exhibit improved glucose regulation, reduced body and liver fat, and diminished hepatic immune infiltration. Intake of the Methylococcu-based diet markedly boosts Parabacteroides abundances in a manner depending on adaptive immunity, and upregulates triple positive (Foxp3+RORγt+IL-17+) regulatory T cells in the small and large intestine. Collectively, these data point to the potential for leveraging the use of McB lysates to improve immunometabolic homeostasis.

Prevalence of Hypertension and Its Associated Risk Factors in a Rural Black Population of Mthatha Town, South Africa

Background: The occurrence of hypertension has been increasing alarmingly in both low and middle-income countries. Despite acknowledging hypertension as the most common life-threatening risk factor for cardiovascular disease (CVD), a dearth of data is available on the prevalence, awareness, and determinants of hypertension in rural parts of South Africa. The principal aim of the current study is to determine the prevalence and associated risk factors of hypertension among a black rural African population from the Mtatha town of Eastern Cape Province. Methods: This was a cross-sectional study, and individuals over 18 years of age were randomly screened using a World Health Organization stepwise questionnaire. Sociodemographic information, anthropometric measurements, fasting blood glucose levels, and three independent blood pressure (BP) readings were measured. Blood pressure measurements were classified according to the American Heart Association guidelines. Univariate and multivariate analyses were performed to determine the significant predictors of hypertension. Results: Of the total participants (n = 556), 71% of individuals had BP scores in the hypertensive range. In univariate analysis, age, westernized diet, education, income, and diabetic status, as well as overweight/obese status were positively associated with the prevalence of hypertension. However, in a multivariate logistic regression analysis only, age, body mass index (BMI), diabetic status, and westernized diet were significantly associated with a higher risk of developing hypertension. Gender, age, and BMI were potential factors having a significant association with the treatment of hypertension. Individuals who did not consider the importance of medicine had higher chances of having their hypertension being untreated. Conclusions: Prevalence of hypertension was high among the black rural African population of Mthatha town. Gender, age, westernized diet, education level, income status, diabetic as well as overweight/obese status were the most significant predictors of hypertension.